Question 37
MediumOriginal questionA shop gives each product a 5-digit code. The first four digits name the product, and the fifth, the check digit, is the sum of the first four digits taken modulo 10.
Which of these codes is valid?
Show the answer and explanation
CorrectNot quiteAnswer D
Correct answer: D
Explanation
For each code, add the first four digits and compare the remainder by 10 with the last digit.
, which ends in 8: 35918 checks. The others give 8 against 7, 7 against 8 and 9 against 8.
- Concept
- Checking a code
- Typical timeTypical
- 120 s
- Your timeYours
- —
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